A hot stock-trading startup is venturing into China

Robinhood, an app that lets people trade stocks for free, has partnered with Chinese search engine Baidu to offers it services in the country.

The deal will let Chinese users invest in the US stocks and ETFs without paying commissions.

"Access to US securities in China is currently very limited and we're excited to change that," Robinhood cofounder Baiju Bhatt said, in a press release Wednesday. "This will be the first time many Chinese citizens will have direct access to the largest stock market in the world at no cost."

Baidu is a Beijing-based Chinese web services company and one of China's leading search engines. Users in China can download Baidu's StockMaster app and create a Robinhood account.

With millions of smartphone users, China offers Robinhood the chance to capture a new user base hungry for stock trading. If successful, the company has the potential to reach millions of users in China, and could set a precedent for other US based startups looking to expand abroad.

But it could still face challenges, including China's increasingly uncertain regulatory regime. Chinese citizens face restrictions on the transfer of capital overseas, for example. Robinhood didn't immediately respond to a query about how it plans to navigate these restrictions.

The company has appointed Amy Gu, the General Manager of Evernote China, to its advisory board. Gu succeeded in growing Evernote's user base in the country to 15 million in 3 years and will help Robinhood navigate China's regulatory grey area, Robinhood said.

The company says it has over 1 million users who have bought and sold more than $6 billion in U.S. stock., saving over $100 million in commission fees. It has raised $66 million from investors including Index and Slow Ventures as well as celebrities like Jared Leto and Snoop Dogg.

Five months ago, Robinhood said it had plans to expand into Europe, however this doesn't appear to have happened yet. The Palo Alto based company does have operations in Australia.